Adhesive



UNITED STATES PATENT OFFICE ADHESIVE Richard Gurley Drew, St. Paul,Minn., assignon to Minnesota Mining & Manufacturing Company, St. Paul,Minn., a corporation of Minnesota No Drawing. Original application July27, 1925,

Serial No. 46,492. Divided and this application June 16, 1926, SerialN0. 116,473

1 Claim.

My present invention relates in general to adhesives or coatings, andmore particularly to soluble adhesives or coatings, and specifically toa non-drying water-soluble adhesive or coating,

(Cl. B l-23.1)

it off with a sharp instrument which tends to mar the underlyingsurface. If such underlying surface has been lacquered or painted, thedanger of marring is obvious. Furthermore, in the case 5 and method ofproducing the same. of the tapes referred to, it frequently happens in 5While the invention has a broad field of usepulling away th tap from tobject t which it fulness, I have found it of peculiar utility forprohas been applied, patches of the lacquer or paint ducing an adhesivecoating for limiting the coat will be lifted from the surface and comeapplication of the spray of liquid finishing mateaway with the tape.Again it frequently haplO rial such, for example, as lacquers inautomobile p s a t s known p s u l a d become body paint shops, and Itherefore find it conventang e in app on and therefore difficult to lentto describe the invention in connection with manage and pply r ly. milrly if n t such practice and product, it being understood, correctly ppin the fi instance. they Often however, that such limited fields ofspecific decannot e ed and pplied in the desired scrlption are employedpurely for purposes of location as they are ruined for such purpose by15 illustration of an example of the utility of the inremoval- Likewisey are Often SO energetic vention ln t several phases, in their adherentaction that the treated coat In t work referred t my improved materialmust be allowed, to set and become firm before may be used as anadhesive for holding protecthe ape is app d the eto. In the cases ofcertive paper aprons against surfaces on which it is tain materials.such s leather and glass, the 20 not desired to apply the lacquer spray,such, for known tapes are objectionable either in that they example, asglass windows, upholstery, rubb will not readily adhere thereto, or ifthey are mats on running boards, bright metal parts, and forced yPressure and time 0 to the like they are not readily cleansed therefrom,tending My improved material may also b applied in the case of leatherto enter into the pores 25 recfly t a surface hi h i later on t befinish d thereof and in the case of glass to become diffused b anapplication of t lacquer spray or b thereover, both of which adds to thecost of the painting, or to a surface which has been finished Operationor detracts from the results produced. in order t prevent mingling of thcolors, as, fo It is known to those who are skilled in the art example,in two-oolor worln that both zinc-oxide cloth tape and, gummed 30 Myimproved t i l may further be applied paper tape tend to deteriorate bythe lapse of time to paper or other suitable backing, in the form Owingto the d y n Out Of t adhesive material, f tape or h th form as may beappropriate and consequent loss of its power to adhere to the for thepurpose contemplated. Object to which it s app ed.

3; It is to be observed that in finishing automobile The principalObjects of my present invention, bodies th lacquers f a plurality ofcolors, therefore, are the provision of an adhesive or difliculties arefound in limiting the application coating W ch is non-drying; theprovision of an f th colors, owing t diffusion of the pray In adhesiveor coating which is water-soluble; the order t tt a clear and clean tline of provision of adhesive'or coating which is mild in 40 marcationbetween the several colors, adhesive its action; the Provision of an vec at g 40 tapes have been used. These are of two general which y be appd to a lacq p ted or types, of whi h th oll d zinc-oxide tape isvarnished surface without injury thereto; the an example of one typeusing a cloth backing provision of an adhesive or coating that when andthe ordinary gummed-paper t i an an applied to a lacquered, varnished orpainted surample of the other type. face may be removed therefromwithout injury 45 Both types of tape referred to present certainthereto; the provision of an adhesive or coating marked objections,among which may be noted t at m y be pp d t leather Other porous thatthe zinc-oxide tape. is not water-soluble material without infiltrationthereinto; the proand when it is removed, a residue remains which visionof an adhesive or coating that ay be has to be cleared away by someexpensive solvent p ed to g ss Without difiusien thereon; the p 50 such,for example, as benzine, gasoline, alcohol or vision of an adherentcoated bac g having One the like, and the ordinary gummed paper tape ormore of the foregoing characteristics; the proadheres s0 tenaciously tothe surface to which it vision of an adherent coated backing which is isapplied that it is necessary either to soak it non-curling; theprovision of an adherent coated 5 in warm water, which involves delay orto scrape backing which may be applied to an object, re

moved therefrom and reapplied without injury to the object or to itself;the provision of an adherent treated coating in which any residuum onremoval is readily soluble in water; the provision of an adherenttreated coating which is highly flexible and adapts itself to curvedcontours of the object to which it is applied; the provision of a newcomposition of matter for the purpose referred to; the provision of animproved method for producing the said composition, together withcertain other objects which will hereinafter appear or be pointed out.

In attaining the foregoing objects and certain additional beneflts andadvantages to be below disclosed I have provided an improved adhesive orcoating which, as above suggested, may be applied either as a spottingfor protective paper aprons, may be applied directly to the object, ormay be embodied in an article such as a tape, which not only avoids thedisadvantages and objections incident to the use of zinc-oxide clothtape and ordinary gummed paper tape, but combines their advantages andexhibits a number of additional marked advantages peculiar to itself.

Among these, may be remarked that it will firmly adhere to the widestrange of materials, and do so indefinitely; that after it has served itspurpose it may be pulled away without soaking or scraping and withoutlifting or injuring the underlying coat; and that after removal anyslight residuum may be removed from the object to which it has beenapplied by water at ordinary temperatures, quickly, safely andeiilcaciously.

As an example of its usefulness, it may be noted that in connection withthe finishing of an automobile body in two colors by means of lacquersprays, as soon as one lacquer color is applied, the tape may be appliedup to the line where the color is to be changed, and then the otherlacquer color applied. As soon as this last operation is completed theimproved tape may be ripped oif without harming the underlying lacquer,since the adhesive does not become sufficiently hard to so cement itselfin position to cause that highly undesirable action. Should the tapehappen to be misapplied and not properly located adjacent the linedesired for color change, it can be readily removed and a second or eventhird attempt made until the exact boundary line desired is accuratelyestablished, and it is easily so applied inasmuch as it does not curlthough it is extremely flexible and accommodates itself to curvedcontours. Because of its mildness in action, it may be promptly appliedto a finished surface, and removed therefrom, and any residuum cleanedoff by a sponge, without fear of injury to the finished surface.Furthermore it requires no special preparation for use, and as itremains fresh indefinitely no special care has to be taken to insure theuse of fresh supplies.

In the preparation of the adhesive or coating according to the presentpreferred practice batches are formed which by weight contain thefollowing ingredients, viz:

and then the mass is dissolved by heat in a steam jacketed kettle. PartII Glycerine (preferably water white GP.) 400 lbs.

Parts I and II are both brought to a temperature about 1". to F. andthen mixed together and stirred thoroughly to produce a homogeneousmass.

Part III Pounds Calcium chloride (commercial 75% pure) 37 Water a 37 Thecalcium chloride is dissolved in the water, and Part III is then addedto the combination of Parts I and II and thoroughly commingledtherewith.

Part IV Beta naphthain alcohol (1% solution) 1/125 part. Part IV is thenadded to the combination of Parts I, II and HI;

Briefly stated, the functions of the several elements in the foregoingcomposition are as follows: glycerine is added to the adhesive glue forthe purpose of imparting flexibility thereto and maintaining suchflexibility; calcium chloride is added because of its hygroscopicqualities in order to prevent the adhesive from drying out, it havingbeen found that normally such addition will preserve the desired degree'of adhesiveness under ordinary conditions of temperature and humidity;and the beta naphthol solution in alcohol is added as a precautionarydisinfectant to inhibit thegrowth of mould-or other fouling.

For certain purposes, such as the combination of high temperature andhigh humidity conditions, I find it at times desirable to add a smallpercentage of alum, (e. g., 5% to 1% of alum on the dry glue, by weight)which tends to coagulate the glue and impart to it an arbitrary body,limiting the amount of water absorbed from the at mosphere, and therebyavoiding any undue or ex cessive amount of stickiness in the resultantproduct.

When embodying my present invention in the form of a tape. I preferablypre-size the cellulose or paper backing on the surface to which thecoating or adhesive is to be applied, in order to limit the penetrationthereof and thereby economize in the amount of such coating required forthe production of a given quantity of tape. My preferred material forsuch pre-sizing is a ten per cent (10%) solution of hide glue in water.

For certain special purposes, such as more closely determining theamount of penetration, or of making a stronger tape, or both, I haveemployed other methods of preparing the tape which I will now proceed todescribe.

In the case of a 30# sheet, I apply a thin coating of asphaltum, andbefore the asphaltum coat has set, a thin tissue sheet of, say, l2#stock is applied to the asphaltum coat, thus making a three-plylaminated structure. My improved coating or adhesive is then applied tothe tissue paper and obviously can penetrate no further than to theasphaltum coating.

Again, I have applied to a 30# sheet a thin coating of asphaltum andbefore the asphaltum has set, further applied to the asphaltum coatedsurface a sheet of reticulated fabric such as is analogous to mosquitonetting or a loosely woven cheese-cloth.

In the latter case, the product is not only materially strengthened, butthe need of using anything in the nature of a slip-sheet to prevent thetape from adhering together as it is wound int coils is obviated.

In the actual practice with adhesive thus far employed by me for thepurposes of my present invention, I have thus far had the best resultswith hide glue as set forth in the foregoing formula. I have, however,had results not so satisfactory with other adhesives such as casein,dextrin, starch, blood albumen, and various water-soluble gums such asacacia, tragacanth, etc.

The preferred material, hide glue and those herein enumerated, to acertain extent are desirable in that they form, with a proper moisteningagent a gelatinous adhesive material and in the claim I mean to includeby such term, materials of the character referred to which, inassociation with a moistening material, have a gelled and adhesiveconsistency.

I have also employed other modifying agents for the purpose of impartingflexibility to the composition. Among these may be mentioned sulphonatedcastor-oil, which though it may render the product too tenaciouslyadhesive for use on lacquered, varnished or painted surfaces, is mostexcellent for use in connection with tapes for closing packages.

I have also employed other sticky substances which are not only more orless adhesive but also more or less hygroscopic, in the production of anon-drying water-soluble adhesive or coating. Among these may bementioned molasses, glucose, honey, and sugar, but thus far I haveattained the best results with the composition as hereinabove set forthin the preferred formula.

While I have described my improved adhesive or coating in connectionwith tape for a particular purpose, it will be appreciated that it has awide field of utility for closing packages, for holding display sheetsagainst sheet glass, and for various uses which may be either temporary,as hereinabove set forth, or permanent relatively as where ordinarygummed tape is not used.

My improved adhesive or coating may also be used for applying to varioussurfaces designs in color, ranging from the simplest to the mostcomplex, either by using it inthe form of a paint or of a piece orpieces of stencilling material, by a method which includes, for example,applying my improved coating, applying a permanent coating thereabout,washing off the first mentioned coating, applying my improved coating tothe second mentioned coating, and then applying a permanent coating tothe desired space covered in the first instance by my said coating.

One of the marked advantages of adhesives or coatings forming thesubject matter of my present invention is the inertness thereof inrespect to acetone, amyl acetate and other solvents of nitrocellulose,which renders them of peculiar availability in connection with finishingoperations wherein nitro-cellulose or compounds of nitro-celluldseandgum varnishes are employed.

'THis application is a division of my prior application, SerialNo.-46,492, filed July 27, 1925.

Having thus described my invention and illustrated its use, what I claimas new and desire to secure by Letters Patent is: e

For use with a normal pressure sensitive sheeted binder coating anadhesive including 100 parts of glue, 400 parts of glycerine, and 37parts of calcium chloride, by weight, the residuum whereof is non-dryingand water soluble.

RICHARD GURLEY DREW.

